Pathologic response to preoperative chemotherapy: a new outcome end point after resection of hepatic colorectal metastases.
OBJECTIVE
The primary goal of this study was to evaluate whether pathologic response to chemotherapy predicts patient survival after preoperative chemotherapy and resection of colorectal liver metastases (CLM). The secondary goal of the study was to identify the clinical predictors of pathologic response.


METHODS
A retrospective review was performed of 305 patients who underwent preoperative irinotecan- or oxaliplatin-based chemotherapy, followed by resection of CLM. Pathologic response was systematically evaluated and reported as the mean of the percentage of cancer cells remaining within each tumor. Univariate and multivariate analyses were performed to identify the predictors of pathologic response and survival.


RESULTS
Cumulative 5-year overall survival rates by pathologic response status were as follows: 75% complete response (no residual cancer cells), 56% major response (1% to 49% residual cancer cells), and 33% minor response (> or = 50% residual cancer cells; complete v major response, P = .037; major v minor response, P = .028). Multivariate analysis revealed that only surgical margin status (P = .050; hazard ratio [HR], 1.77) and pathologic response (major response: P = .034; HR, 4.80; minor response: P = .007; HR, 6.93) were independent predictors of survival. Multivariate analysis of the predictors of pathologic response revealed that carcinoembryonic antigen level < or = 5 ng/mL, tumor size < or = 3 cm, and chemotherapy with fluoropyrimidine plus oxaliplatin and bevacizumab were independent predictors of pathologic response.


CONCLUSIONS
Pathologic response predicts survival after preoperative chemotherapy and resection of CLM. Degree of pathologic response represents a new outcome end point for prognosis after resection of CLM.
Blazer
Dan G
DG
Department of Surgical Oncology, Gastrointestinal Medical Oncology, and Pathology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030-4009, USA.
Kishi
Yoji
Y
Maru
Dipen M
DM
Kopetz
Scott
S
Chun
Yun Shin
YS
Overman
Michael J
MJ
Fogelman
David
D
Eng
Cathy
C
Chang
David Z
DZ
Wang
Huamin
H
Zorzi
Daria
D
Ribero
Dario
D
Ellis
Lee M
LM
Glover
Katrina Y
KY
Wolff
Robert A
RA
Curley
Steven A
SA
Abdalla
Eddie K
EK
Vauthey
Jean-Nicolas
JN
D000230:Adenocarcinoma / Q000556:secondary* / Q000601:surgery*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000911:Antibodies, Monoclonal / Q000008:administration & dosage; D061067:Antibodies, Monoclonal, Humanized; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D000068258:Bevacizumab; D002166:Camptothecin / Q000008:administration & dosage / Q000031:analogs & derivatives; D017024:Chemotherapy, Adjuvant; D015179:Colorectal Neoplasms / Q000401:mortality / Q000473:pathology*; D005260:Female; D006498:Hepatectomy; D006801:Humans; D000077146:Irinotecan; D008113:Liver Neoplasms / Q000188:drug therapy / Q000556:secondary* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009944:Organoplatinum Compounds / Q000008:administration & dosage; D000077150:Oxaliplatin; D015996:Survival Rate
D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D009944:Organoplatinum Compounds; D000077150:Oxaliplatin; D000068258:Bevacizumab; D000077146:Irinotecan; D002166:Camptothecin